1. Field of the Invention
The present invention relates to a touch panel device, and more particularly to a touch panel liquid crystal display device having a polarizer and a touch panel.
2. Description of the Related Art
Touch panels are computer peripheral devices that are commonly installed on display surfaces of image display devices, such as Cathode Ray Tubes (CRTs), Liquid Crystal Displays (LCDs), Field Emission Displays (FEDs), Plasma Display Panel (PDPs), and Electro Luminescence Devices (ELDs). The touch panel is activated by a user applying pressure on the touch panel to enter predetermined information into a computer input terminal.
FIG. 1 is a schematic view of a liquid crystal display device having a touch panel according to the related art. In FIG. 1, a touch panel 32 is mounted onto a liquid crystal display panel 31, and a backlight 33 is provided behind the liquid crystal panel 31. The touch panel 32 is electrically interconnected to a touch controller 34 by a signal line 36, and the touch controller 34 is electrically interconnected to a computer system 35. During operation of the touch panel, if a predetermined pressure is applied to a contact point of the touch panel 32, a voltage value of the contact point is calculated by the touch controller 34 to recognize the coordinates of the contact point.
FIG. 2 is a perspective view of a touch panel of the liquid crystal display device shown in FIG. 1. In FIG. 2, the touch panel 32 includes an upper plate 32a and a lower plate 32b, a liquid crystal display panel 31 that consists of an upper plate 31a and a lower plate 31b, and a polarizer 4 formed between the touch panel 32 and the liquid crystal display panel 31. The touch panel 32 includes an upper electrode formed on an upper substrate of the upper plate 32a, a lower electrode formed on a lower substrate of the lower plate 32b, and a spacer for maintaining gap between the upper plate 32a and the lower plate 32b. 
The liquid crystal display panel 31 includes an upper electrode formed on an upper substrate of the upper plate 31a, a plurality of lower electrodes formed on a lower substrate of the lower plate 31b, alignment films (not shown) formed on the upper and lower electrodes, a liquid crystal material formed on the alignment films, and a spacer for controlling a cell gap between the upper plate 31a and the lower plate 31b. In addition, a sealant material that bonds and fixes the upper plate 31a and the lower plate 31b together is formed to prevent moisture and impurities from permeating from an exterior of the liquid crystal display panel 31 to an interior of the liquid crystal display panel 31 along an edge of the upper plate 31a and the lower plate 31b. The polarizer 4 is formed between the lower plate 32b of the touch panel 32 and the upper plate 32a of the liquid crystal display panel 32, wherein the polarizer converts visible light into polarized light.
A first adhesive 39a is formed between the lower plate 32b of the touch panel 32 and the polarizer 4, a second adhesive 39b is formed between the upper plate 31a of the liquid crystal display panel 31 and the polarizer 4. The touch panel 32 is bonded with the liquid crystal display panel 31 by the first adhesive 39a and the second adhesive 39b formed with the polarizer 4 therebetween.
When comparing the first and the second adhesives 39a and 39b, the adhesive strength of the first adhesive 39a is not weaker than that of the second adhesive 39b. Accordingly, when separating the touch panel 32 from the polarizer 4 and the liquid crystal display panel 31 in order to repair the touch panel 32, the polarizer 4 is damaged because the polarizer 4 is separated along with the touch panel 32.